// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
// Distributed under the MIT License (http://opensource.org/licenses/MIT)

#pragma once

// Helper RAII over winsock udp client socket.
// Will throw on construction if socket creation failed.

#include <spdlog/common.h>
#include <spdlog/details/os.h>
#include <spdlog/details/windows_include.h>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <winsock2.h>
#include <ws2tcpip.h>

#if defined(_MSC_VER)
#pragma comment(lib, "Ws2_32.lib")
#pragma comment(lib, "Mswsock.lib")
#pragma comment(lib, "AdvApi32.lib")
#endif

namespace spdlog {
namespace details {
    class udp_client
    {
        static constexpr int TX_BUFFER_SIZE = 1024 * 10;
        SOCKET socket_ = INVALID_SOCKET;
        sockaddr_in addr_ = {};

        static void init_winsock_()
        {
            WSADATA wsaData;
            auto rv = ::WSAStartup(MAKEWORD(2, 2), &wsaData);
            if (rv != 0)
            {
                throw_winsock_error_("WSAStartup failed", ::WSAGetLastError());
            }
        }

        static void throw_winsock_error_(const std::string& msg, int last_error)
        {
            char buf[512];
            ::FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                             NULL,
                             last_error,
                             MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                             buf,
                             (sizeof(buf) / sizeof(char)),
                             NULL);

            throw_spdlog_ex(fmt_lib::format("udp_sink - {}: {}", msg, buf));
        }

        void cleanup_()
        {
            if (socket_ != INVALID_SOCKET)
            {
                ::closesocket(socket_);
            }
            socket_ = INVALID_SOCKET;
            ::WSACleanup();
        }

    public:
        udp_client(const std::string& host, uint16_t port)
        {
            init_winsock_();

            addr_.sin_family = PF_INET;
            addr_.sin_port = htons(port);
            addr_.sin_addr.s_addr = INADDR_ANY;
            if (InetPtonA(PF_INET, host.c_str(), &addr_.sin_addr.s_addr) != 1)
            {
                int last_error = ::WSAGetLastError();
                ::WSACleanup();
                throw_winsock_error_("error: Invalid address!", last_error);
            }

            socket_ = ::socket(PF_INET, SOCK_DGRAM, 0);
            if (socket_ == INVALID_SOCKET)
            {
                int last_error = ::WSAGetLastError();
                ::WSACleanup();
                throw_winsock_error_("error: Create Socket failed", last_error);
            }

            int option_value = TX_BUFFER_SIZE;
            if (::setsockopt(socket_, SOL_SOCKET, SO_SNDBUF, reinterpret_cast<const char*>(&option_value), sizeof(option_value)) < 0)
            {
                int last_error = ::WSAGetLastError();
                cleanup_();
                throw_winsock_error_("error: setsockopt(SO_SNDBUF) Failed!", last_error);
            }
        }

        ~udp_client() { cleanup_(); }

        SOCKET fd() const { return socket_; }

        void send(const char* data, size_t n_bytes)
        {
            socklen_t tolen = sizeof(struct sockaddr);
            if (::sendto(socket_, data, static_cast<int>(n_bytes), 0, (struct sockaddr*)&addr_, tolen) == -1)
            {
                throw_spdlog_ex("sendto(2) failed", errno);
            }
        }
    };
}  // namespace details
}  // namespace spdlog
